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Le N, Vu TD, Palazzo I, Pulya R, Kim Y, Blackshaw S, Hoang T. Robust reprogramming of glia into neurons by inhibition of Notch signaling and nuclear factor I (NFI) factors in adult mammalian retina. SCIENCE ADVANCES 2024; 10:eadn2091. [PMID: 38996013 PMCID: PMC11244444 DOI: 10.1126/sciadv.adn2091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 06/10/2024] [Indexed: 07/14/2024]
Abstract
Generation of neurons through direct reprogramming has emerged as a promising therapeutic approach for treating neurodegenerative diseases. In this study, we present an efficient method for reprogramming retinal glial cells into neurons. By suppressing Notch signaling by disrupting either Rbpj or Notch1/2, we induced mature Müller glial cells to reprogram into bipolar- and amacrine-like neurons. We demonstrate that Rbpj directly activates both Notch effector genes and genes specific to mature Müller glia while indirectly repressing expression of neurogenic basic helix-loop-helix (bHLH) factors. Combined loss of function of Rbpj and Nfia/b/x resulted in conversion of nearly all Müller glia to neurons. Last, inducing Müller glial proliferation by overexpression of dominant-active Yap promotes neurogenesis in both Rbpj- and Nfia/b/x/Rbpj-deficient Müller glia. These findings demonstrate that Notch signaling and NFI factors act in parallel to inhibit neurogenic competence in mammalian Müller glia and help clarify potential strategies for regenerative therapies aimed at treating retinal dystrophies.
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Affiliation(s)
- Nguyet Le
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Trieu-Duc Vu
- Department of Ophthalmology and Visual Sciences, University of Michigan School of Medicine, Ann Arbor, MI 48105
- Michigan Neuroscience Institute, University of Michigan School of Medicine, Ann Arbor, MI 48105, USA
| | - Isabella Palazzo
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ritvik Pulya
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yehna Kim
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Seth Blackshaw
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Thanh Hoang
- Department of Ophthalmology and Visual Sciences, University of Michigan School of Medicine, Ann Arbor, MI 48105
- Michigan Neuroscience Institute, University of Michigan School of Medicine, Ann Arbor, MI 48105, USA
- Department of Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, MI 48105, USA
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Le N, Vu TD, Palazzo I, Pulya R, Kim Y, Blackshaw S, Hoang T. Robust reprogramming of glia into neurons by inhibition of Notch signaling and NFI factors in adult mammalian retina. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.29.560483. [PMID: 37961663 PMCID: PMC10634926 DOI: 10.1101/2023.10.29.560483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Generation of neurons through direct reprogramming has emerged as a promising therapeutic approach for neurodegenerative diseases. Despite successful applications in vitro , in vivo implementation has been hampered by low efficiency. In this study, we present a highly efficient strategy for reprogramming retinal glial cells into neurons by simultaneously inhibiting key negative regulators. By suppressing Notch signaling through the removal of its central mediator Rbpj, we induced mature Müller glial cells to reprogram into bipolar and amacrine neurons in uninjured adult mouse retinas, and observed that this effect was further enhanced by retinal injury. We found that specific loss of function of Notch1 and Notch2 receptors in Müller glia mimicked the effect of Rbpj deletion on Müller glia-derived neurogenesis. Integrated analysis of multiome (scRNA- and scATAC-seq) and CUT&Tag data revealed that Rbpj directly activates Notch effector genes and genes specific to mature Müller glia while also indirectly represses the expression of neurogenic bHLH factors. Furthermore, we found that combined loss of function of Rbpj and Nfia/b/x resulted in a robust conversion of nearly all Müller glia to neurons. Finally, we demonstrated that inducing Müller glial proliferation by AAV (adeno-associated virus)-mediated overexpression of dominant- active Yap supports efficient levels of Müller glia-derived neurogenesis in both Rbpj - and Nfia/b/x/Rbpj - deficient Müller glia. These findings demonstrate that, much like in zebrafish, Notch signaling actively represses neurogenic competence in mammalian Müller glia, and suggest that inhibition of Notch signaling and Nfia/b/x in combination with overexpression of activated Yap could serve as an effective component of regenerative therapies for degenerative retinal diseases.
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Zhang X, Leavey P, Appel H, Makrides N, Blackshaw S. Molecular mechanisms controlling vertebrate retinal patterning, neurogenesis, and cell fate specification. Trends Genet 2023; 39:736-757. [PMID: 37423870 PMCID: PMC10529299 DOI: 10.1016/j.tig.2023.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 07/11/2023]
Abstract
This review covers recent advances in understanding the molecular mechanisms controlling neurogenesis and specification of the developing retina, with a focus on insights obtained from comparative single cell multiomic analysis. We discuss recent advances in understanding the mechanisms by which extrinsic factors trigger transcriptional changes that spatially pattern the optic cup (OC) and control the initiation and progression of retinal neurogenesis. We also discuss progress in unraveling the core evolutionarily conserved gene regulatory networks (GRNs) that specify early- and late-state retinal progenitor cells (RPCs) and neurogenic progenitors and that control the final steps in determining cell identity. Finally, we discuss findings that provide insight into regulation of species-specific aspects of retinal patterning and neurogenesis, including consideration of key outstanding questions in the field.
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Affiliation(s)
- Xin Zhang
- Department of Ophthalmology, Columbia University School of Medicine, New York, NY, USA; Department of Pathology and Cell Biology, Columbia University School of Medicine, New York, NY, USA.
| | - Patrick Leavey
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Haley Appel
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Neoklis Makrides
- Department of Ophthalmology, Columbia University School of Medicine, New York, NY, USA
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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4
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Buck TM, Quinn PMJ, Pellissier LP, Mulder AA, Jongejan A, Lu X, Boon N, Koot D, Almushattat H, Arendzen CH, Vos RM, Bradley EJ, Freund C, Mikkers HMM, Boon CJF, Moerland PD, Baas F, Koster AJ, Neefjes J, Berlin I, Jost CR, Wijnholds J. CRB1 is required for recycling by RAB11A+ vesicles in human retinal organoids. Stem Cell Reports 2023; 18:1793-1810. [PMID: 37541258 PMCID: PMC10545476 DOI: 10.1016/j.stemcr.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 08/06/2023] Open
Abstract
CRB1 gene mutations can cause early- or late-onset retinitis pigmentosa, Leber congenital amaurosis, or maculopathy. Recapitulating human CRB1 phenotypes in animal models has proven challenging, necessitating the development of alternatives. We generated human induced pluripotent stem cell (iPSC)-derived retinal organoids of patients with retinitis pigmentosa caused by biallelic CRB1 mutations and evaluated them against autologous gene-corrected hiPSCs and hiPSCs from healthy individuals. Patient organoids show decreased levels of CRB1 and NOTCH1 expression at the retinal outer limiting membrane. Proximity ligation assays show that human CRB1 and NOTCH1 can interact via their extracellular domains. CRB1 patient organoids feature increased levels of WDFY1+ vesicles, fewer RAB11A+ recycling endosomes, decreased VPS35 retromer complex components, and more degradative endolysosomal compartments relative to isogenic control organoids. Taken together, our data demonstrate that patient-derived retinal organoids enable modeling of retinal degeneration and highlight the importance of CRB1 in early endosome maturation receptor recycling in the retina.
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Affiliation(s)
- Thilo M Buck
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands
| | - Peter M J Quinn
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands
| | - Lucie P Pellissier
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam 1105 BA, the Netherlands
| | - Aat A Mulder
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), Leiden 2300 RC, the Netherlands
| | - Aldo Jongejan
- Bioinformatics Laboratory, Epidemiology & Data Science, Amsterdam University Medical Centers, Amsterdam 1105 AZ, the Netherlands
| | - Xuefei Lu
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands
| | - Nanda Boon
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands
| | - Daniëlle Koot
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands
| | - Hind Almushattat
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands
| | | | - Rogier M Vos
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam 1105 BA, the Netherlands
| | - Edward J Bradley
- Department of Genome Analysis, Amsterdam University Medical Centers, Amsterdam 1105 AZ, the Netherlands
| | - Christian Freund
- Leiden University Medical Center hiPSC Hotel, Leiden 2333 ZA, the Netherlands
| | - Harald M M Mikkers
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), Leiden 2300 RC, the Netherlands; Leiden University Medical Center hiPSC Hotel, Leiden 2333 ZA, the Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands; Department of Ophthalmology, Amsterdam University Medical Centers, Academic Medical Center, University of Amsterdam, Amsterdam 1000 AE, the Netherlands
| | - Perry D Moerland
- Bioinformatics Laboratory, Epidemiology & Data Science, Amsterdam University Medical Centers, Amsterdam 1105 AZ, the Netherlands
| | - Frank Baas
- Department of Genome Analysis, Amsterdam University Medical Centers, Amsterdam 1105 AZ, the Netherlands; Department of Clinical Genetics/LDGA, Leiden University Medical Center, Leiden 2333 ZA, the Netherlands
| | - Abraham J Koster
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), Leiden 2300 RC, the Netherlands
| | - Jacques Neefjes
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), Leiden 2300 RC, the Netherlands
| | - Ilana Berlin
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), Leiden 2300 RC, the Netherlands
| | - Carolina R Jost
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), Leiden 2300 RC, the Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands; Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam 1105 BA, the Netherlands.
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Faber S, Letteboer SJF, Junger K, Butcher R, Tammana TVS, van Beersum SEC, Ueffing M, Collin RWJ, Liu Q, Boldt K, Roepman R. PDE6D Mediates Trafficking of Prenylated Proteins NIM1K and UBL3 to Primary Cilia. Cells 2023; 12:cells12020312. [PMID: 36672247 PMCID: PMC9857354 DOI: 10.3390/cells12020312] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 01/02/2023] [Accepted: 01/09/2023] [Indexed: 01/18/2023] Open
Abstract
Mutations in PDE6D impair the function of its cognate protein, phosphodiesterase 6D (PDE6D), in prenylated protein trafficking towards the ciliary membrane, causing the human ciliopathy Joubert Syndrome (JBTS22) and retinal degeneration in mice. In this study, we purified the prenylated cargo of PDE6D by affinity proteomics to gain insight into PDE6D-associated disease mechanisms. By this approach, we have identified a specific set of PDE6D-interacting proteins that are involved in photoreceptor integrity, GTPase activity, nuclear import, or ubiquitination. Among these interacting proteins, we identified novel ciliary cargo proteins of PDE6D, including FAM219A, serine/threonine-protein kinase NIM1 (NIM1K), and ubiquitin-like protein 3 (UBL3). We show that NIM1K and UBL3 localize inside the cilium in a prenylation-dependent manner. Furthermore, UBL3 also localizes in vesicle-like structures around the base of the cilium. Through affinity proteomics of UBL3, we confirmed its strong interaction with PDE6D and its association with proteins that regulate small extracellular vesicles (sEVs) and ciliogenesis. Moreover, we show that UBL3 localizes in specific photoreceptor cilium compartments in a prenylation-dependent manner. Therefore, we propose that UBL3 may play a role in the sorting of proteins towards the photoreceptor outer segment, further explaining the development of PDE6D-associated retinal degeneration.
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Affiliation(s)
- Siebren Faber
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Stef J. F. Letteboer
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Katrin Junger
- Division of Experimental Ophthalmology and Medical Proteome Center, Center of Ophthalmology, University of Tübingen, 72076 Tübingen, Germany
| | - Rossano Butcher
- Department of Ophthalmology, Ocular Genomics Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA 02115, USA
| | - Trinadh V. Satish Tammana
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Sylvia E. C. van Beersum
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Marius Ueffing
- Division of Experimental Ophthalmology and Medical Proteome Center, Center of Ophthalmology, University of Tübingen, 72076 Tübingen, Germany
| | - Rob W. J. Collin
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Qin Liu
- Department of Ophthalmology, Ocular Genomics Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA 02115, USA
| | - Karsten Boldt
- Division of Experimental Ophthalmology and Medical Proteome Center, Center of Ophthalmology, University of Tübingen, 72076 Tübingen, Germany
| | - Ronald Roepman
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
- Correspondence:
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Chew SH, Martinez C, Chirco KR, Kandoi S, Lamba DA. Timed Notch Inhibition Drives Photoreceptor Fate Specification in Human Retinal Organoids. Invest Ophthalmol Vis Sci 2022; 63:12. [PMID: 36129723 PMCID: PMC9513742 DOI: 10.1167/iovs.63.10.12] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Transplanting photoreceptors from human pluripotent stem cell–derived retinal organoids have the potential to reverse vision loss in affected individuals. However, transplantable photoreceptors are only a subset of all cells in the organoids. Hence, the goal of our current study was to accelerate and synchronize photoreceptor differentiation in retinal organoids by inhibiting the Notch signaling pathway at different developmental time-points using a small molecule, PF-03084014 (PF). Methods Human induced pluripotent stem cell– and human embryonic stem cells–derived retinal organoids were treated with 10 µM PF for 3 days starting at day 45 (D45), D60, D90, and D120 of differentiation. Organoids were collected at post-treatment days 14, 28, and 42 and analyzed for progenitor and photoreceptor markers and Notch pathway inhibition by immunohistochemistry (IHC), quantitative PCR, and bulk RNA sequencing (n = 3–5 organoids from three independent experiments). Results Retinal organoids collected after treatment showed a decrease in progenitor markers (KI67, VSX2, PAX6, and LHX2) and an increase in differentiated pan-photoreceptor markers (OTX2, CRX, and RCVRN) at all organoid stages except D120. PF-treated organoids at D45 and D60 exhibited an increase in cone photoreceptor markers (RXRG and ARR3). PF treatment at D90 revealed an increase in cone and rod photoreceptors markers (ARR3, NRL, and NR2E3). Bulk RNA sequencing analysis mirrored the immunohistochemistry data and quantitative PCR confirmed Notch effector inhibition. Conclusions Timing the Notch pathway inhibition in human retinal organoids to align with progenitor competency stages can yield an enriched population of early cone or rod photoreceptors.
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Affiliation(s)
- Shereen H Chew
- Department of Ophthalmology, University of California San Francisco, California, United States.,Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California, United States
| | - Cassandra Martinez
- Department of Ophthalmology, University of California San Francisco, California, United States.,Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California, United States
| | - Kathleen R Chirco
- Department of Ophthalmology, University of California San Francisco, California, United States.,Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon, United States
| | - Sangeetha Kandoi
- Department of Ophthalmology, University of California San Francisco, California, United States.,Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California, United States
| | - Deepak A Lamba
- Department of Ophthalmology, University of California San Francisco, California, United States.,Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, California, United States
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MYCN induces cell-specific tumorigenic growth in RB1-proficient human retinal organoid and chicken retina models of retinoblastoma. Oncogenesis 2022; 11:34. [PMID: 35729105 PMCID: PMC9213451 DOI: 10.1038/s41389-022-00409-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 06/03/2022] [Accepted: 06/07/2022] [Indexed: 11/09/2022] Open
Abstract
Retinoblastoma is a rare, intraocular paediatric cancer that originates in the neural retina and is most frequently caused by bi-allelic loss of RB1 gene function. Other oncogenic mutations, such as amplification and increased expression of the MYCN gene, have been found even with proficient RB1 function. In this study, we investigated whether MYCN over-expression can drive carcinogenesis independently of RB1 loss-of-function mutations. The aim was to elucidate the events that result in carcinogenesis and identify the cancer cell-of-origin. We used the chicken retina, a well-established model for studying retinal neurogenesis, and established human embryonic stem cell-derived retinal organoids as model systems. We over-expressed MYCN by electroporation of piggyBac genome-integrating expression vectors. We found that over-expression of MYCN induced tumorigenic growth with high frequency in RB1-proficient chicken retinas and human organoids. In both systems, the tumorigenic cells expressed markers for undifferentiated cone photoreceptor/horizontal cell progenitors. The over-expression resulted in metastatic retinoblastoma within 7–9 weeks in chicken. Cells expressing MYCN could be grown in vitro and, when orthotopically injected, formed tumours that infiltrated the sclera and optic nerve and expressed markers for cone progenitors. Investigation of the tumour cell phenotype determined that the potential for neoplastic growth was embryonic stage-dependent and featured a cell-specific resistance to apoptosis in the cone/horizontal cell lineage, but not in ganglion or amacrine cells. We conclude that MYCN over-expression is sufficient to drive tumorigenesis and that a cell-specific resistance to apoptosis in the cone/horizontal cell lineage mediates the cancer phenotype. ![]()
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Fishman ES, Han JS, La Torre A. Oscillatory Behaviors of microRNA Networks: Emerging Roles in Retinal Development. Front Cell Dev Biol 2022; 10:831750. [PMID: 35186936 PMCID: PMC8847441 DOI: 10.3389/fcell.2022.831750] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 01/07/2022] [Indexed: 01/02/2023] Open
Abstract
A broad repertoire of transcription factors and other genes display oscillatory patterns of expression, typically ranging from 30 min to 24 h. These oscillations are associated with a variety of biological processes, including the circadian cycle, somite segmentation, cell cycle, and metabolism. These rhythmic behaviors are often prompted by transcriptional feedback loops in which transcriptional activities are inhibited by their corresponding gene target products. Oscillatory transcriptional patterns have been proposed as a mechanism to drive biological clocks, the molecular machinery that transforms temporal information into accurate spatial patterning during development. Notably, several microRNAs (miRNAs) -small non-coding RNA molecules-have been recently shown to both exhibit rhythmic expression patterns and regulate oscillatory activities. Here, we discuss some of these new findings in the context of the developing retina. We propose that miRNA oscillations are a powerful mechanism to coordinate signaling pathways and gene expression, and that addressing the dynamic interplay between miRNA expression and their target genes could be key for a more complete understanding of many developmental processes.
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Affiliation(s)
| | | | - Anna La Torre
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA, United States
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